Combustion and Flame 144 (2006) 103–111 www.elsevier.com/locate/combustflame The effect of mono-dispersed water mist on the suppression of laminar premixed hydrogen–, methane–, and propane–air flames Abhijit U. Modak a , Angel Abbud-Madrid b , Jean-Pierre Delplanque a,1 , Robert J. Kee a,∗ a Engineering Division, Colorado School of Mines, Golden, CO 80401, USA b Center for the Commercial Applications of Combustion in Space, Colorado School of Mines, Golden, CO 80401, USA Received 2 November 2004; received in revised form 19 June 2005; accepted 3 July 2005 Available online 19 August 2005 Abstract Computational simulations are used to predict and understand the influence of fine water mists on the sup- pression of laminar, freely propagating methane–, propane–, and hydrogen–air atmospheric-pressure premixed flames. The model solves a coupled, chemically reacting, two-phase-flow problem. Flame suppression is measured in terms of a reduction in burning velocity. The effects of droplet diameter, net water loading, and fuel–air stoi- chiometry are reported. The results show similar qualitative features for all the flames. Generally speaking, smaller droplets are more effective than the larger droplets. Sufficiently small droplets (approximately 10 μm diameter for methane–air flames) are in a small-droplet limit, where even smaller droplets have the same suppression charac- teristics for the same net mass loading. Droplets above a certain diameter (approximately 30 μm for methane–air flames) lead to a turning-point extinction, where the burning velocity at the turning point is approximately half of the unperturbed burning velocity without any water-mist loading.  2005 The Combustion Institute. Published by Elsevier Inc. All rights reserved. Keywords: Water mist; Flame suppression; Computational modeling; Laminar flames; Premixed flames 1. Introduction This paper extends and applies the computational model developed by Yang and Kee to predict the in- fluence of fine water mist on premixed flame suppres- sion [1]. The previous work reported details of the * Corresponding author. E-mail address: rjkee@mines.edu (R.J. Kee). 1 Present address: MAE Department, Univ. of California, Davis, CA. computational algorithm and illustrated the approach using stoichiometric methane–air flames. The present paper, which reports results for hydrogen–, methane–, and propane–air flames, also considers the effects of stoichiometry ranging from lean through rich condi- tions. Fine water mist is known to be an effective fire- suppression agent and is incorporated into commer- cial practice [2]. Very fine mists (droplet sizes of tens of micrometers) are well suited for use in areas such as electronic equipment compartments because they do not cause damage by wetting surfaces. Neverthe- 0010-2180/$ – see front matter  2005 The Combustion Institute. Published by Elsevier Inc. All rights reserved. doi:10.1016/j.combustflame.2005.07.003